1. Field of the Invention
The present invention relates to a detachable stop useful in conjunction with door closing mechanisms having a piston/rod combination operating within a cylinder. The stop is positionable along the piston rod exteriorly of the cylinder at a selected point to prevent the rod from being drawn in to the cylinder, thereby maintaining the door in a generally open or partially open position.
2. Description Of the Prior Art
The use of door closing mechanisms having a rod and associated piston operating within a cylinder is well known. For instance, in residential applications, it is well known to connect such mechanism between the door and its frame to act as a shock absorber or dampener against the action of a closing force such as a spring or a partial vacuum within the cylinder. Such mechanisms have also been used in many other applications such as hatchback doors on motor vehicles and even unrelated uses such as closure devices on umbrellas.
It has been known to provide different types of stops in conjunction with such closing mechanisms which allow the door to be closed only partially, thereby temporarily maintaining the door in the desired position against the closing force. One of the more common types of prior art devices consists of a stop washer mounted on the piston rod. The washer is wedged between the rod and the cylinder to prevent the rod from being drawn in to the cylinder.
Another type of the prior art is shown in U.S. Pat. No. 1,892,811 which utilizes a stop comprising a collar positioned around the rod exteriorly of the cylinder, with a thumbscrew that can be tighten to fix the collar at the desired location along the cylinder An alternative embodiment comprises a lever in place of a collar, which acts in much the same fashion as the conventional stop washer. One of the problems with this type of device is that the stop must be put in position on the rod when the closing mechanism is installed. Consequently, each closing mechanism requires its own stopper.
Another example of the prior art is shown in U.S. Pat. No. 5,024,303 which discloses a locking mechanism for hatchbacks. In this instance, the locking mechanism comprises a body having two portions hinged together and defining a central aperture, which is positionable around the rod at a desired location. The two portions of the body member are secured by fastening means such as a hinge pin. Again, the body member may be locked in the desired position by a thumbscrew. The type of arrangement taught in this patent, however, is not easily detachable once in place. Consequently, each locking mechanism is generally operable only in conjunction with the closing mechanism on which it is originally installed.
One drawback of all of the prior art devices is that if the original stop should fail for any reason, the whole door shock must be replaced or at least disassembled to remove the failed stop and add a replacement stop.